Title

US/Australia Collaborative Research Project on Corrosion Fatigue in D6AC Steel Joints

Date

1978

Index Abstract

Not Available

Photo Quality

Incomplete

Report Number

AFML TR 78-150

Creator

Harmsworth, C. L.

Kemsley, D. S.

Finney, J. M.

Corporate Author

Air Force Materials Laboratory

Laboratory

Air Force Materials Laboratory

Extent

100

Identifier

ADA076197

Access Rights

Approved for public release; distribution unlimited.

Distribution Classification

1

DoD Project

2418

DoD Task

241807

DTIC Record Exists

Yes

Distribution Conflict

No

Abstract

A U.S./Australian Program has been conducted to determine the effect of manufacturing-induced and environmental corrosion on D6AC steel Taper-Lok bolted joints as used in the F-111 aircraft. Under constant amplitude, traces of distilled water or concentrated hydrochloric acid in the bolt holes did not reduce fatigue life. Under spectrum loading traces of water did not affect fatigue life but traces of hydrochloric acid reduced the mean fatigue life of the joint by a factor of 110. The results of further constant amplitude tests and a limited series of spectrum tests confirmed previous findings that the life of those original joints in the F-111 which were manufactured using a six-flute hand reamer could be appreciably extended by rework with an 18-flute tapered reamer as used in later F-111 production. Other rework procedures involving cold working of the hole by a mandrel or specially designed fasteners showed little improvement when used in this relatively high-strength steel joint material. The effects of improved sealants and the capability of ultrasonic and magnetic NDI techniques for inspection of cracks at fastener holes were also investigated. It is concluded that the life of uncontaminated, properly fabricated and sealed D6AC steel joints as used in the F-111 wing carry through should not be a source of fatigue failure during a normal aircraft lifetime.

Report Availability

Full text available by request

Date Issued

1978-12

Provenance

Bombardier/Aero

Type

report

Format

100 pages ; 28 cm.